1. Field of the Invention
The present invention relates to an electrolyzed water generator which produces acidic and alkaline electrolyzed water, by electrolyzing raw water fed into a pair of electrolysis chambers arranged opposite to each other through an ion permeable diaphragm, and by applying a voltage to a pair of electrodes respectively arranged in the electrolysis chambers in a manner sandwiching the diaphragm. More specifically, the present invention relates to an electrolytic cell in the electrolyzed water generator.
2. Description of the Related Art
There is known an electrolyzed water generator which produces electrolyzed water by use of an electrolytic cell comprising a pair of electrolysis chambers arranged opposite to each other through an ion permeable diaphragm and a pair of electrodes respectively arranged in the electrolysis chambers in a manner sandwiching the diaphragm. In the electrolyzed water generator, electrolyte-containing raw water is fed into each of the electrolysis chambers, the raw water is electrolyzed by applying a voltage to the pair of electrodes, and consequently, acidic electrolyzed water can be produced in the anodic electrolysis chamber, and on the other hand, alkaline electrolyzed water can be produced in the cathodic electrolysis chamber.
In the electrolytic cell in the electrolyzed water generator, the electrodes are each arranged usually with a space from the diaphragm. However, in this structure, the electrodes arranged in a manner sandwiching the diaphragm are separated from each other with a large space therebetween, and hence the electric resistance between the electrodes is large, resulting in a problem that the electrolysis efficiency in relation to the applied electric power is low.
For the purpose of solving the above described problem, for example, there has been proposed an electrolytic cell in which the electrodes are separated from each other with a reduced space by bringing the diaphragm into contact with the electrodes each formed by laminating a porous electrode material made of a plain-woven wire mesh and a punched metal sheet (for example, see Japanese Patent Laid-Open No. 2001-73177). According to this electrolytic cell, raw water is made to circulate inside the porous electrode material, and consequently the contact area between the raw water and each of the electrodes can be made large. In addition, according to this electrolytic cell, the electrolysis efficiency can be improved to some extent in relation to the applied electric power.
However, in the electrolytic cell disclosed in the above publication, the circulation resistance is large, and hence when the amount of electrolyzed water produced in a unit time is increased, the equipment concerned inevitably becomes large insize. The mentioned large circulation resistance is caused by the fact that raw water is made to circulate inside the porous electrode material.
Under these circumstances, the present inventors have proposed an electrolytic cell in which a pair of electrodes are formed so as to respectively adhere to both surfaces of an ion permeable diaphragm, and there is used a membrane-electrode assembly in which the electrodes themselves are provided with ion permeability (see Japanese Patent Laid-Open Nos. 2005-144239 and 2005-144240). According to the membrane-electrode assembly, only the diaphragm intervenes between both electrodes, so that the electrolysis efficiency in relation to the applied electric power can be enhanced, and in addition, the equipment can be downsized.
However, in the above described membrane-electrode assembly, it is not easy to connect lead wires to the electrodes, and it is not easy to supply electric power through the lead wires. It is possible to make current collectors, in place of the lead wires, in contact with the surfaces of the electrodes. However, when the electrodes are formed of a porous material having fine pores, namely, so-called a microporous material, the surface resistance of the electrodes is high. Accordingly, even when the current collectors are brought into contact with the electrode surfaces, it is not easy to supply electric power from the current collectors to the electrodes, and hence further improvement is desired.